Study the Behavior of Ground-Supported Cylindrical Tanks Considering the Soil Structure Interaction Using Finite Element Method FEM

Abstract

The ground-supported Cylindrical Steel tanks are widely used in industrial and service domains to store various types of liquid. As a result of neglecting the interaction between the fluid and tank from one side and the interaction between the tanks and soil beneath them from the other side, it will likely be exposed to huge damages during and post-earthquakes. In this paper, the fluid-tank system considering Soil Structure interaction (SSI) has been studied. The 3D model has forming for the soil, tank and fluid in the finite element program (ABAQUS) to examine the two types of tanks. Two types of soil (hard-Conglomerate & silty gravel) and the frequency content of several earthquake records have been investigated.  The results have apprenticed that the shear force of the water tank in the silty gravel soil is increasing by about 60% in the hard soil and may decrease by about 10% -20%. These ratios vary depending on the Frequency content of the seismic record and the role of properties of silty gravel soil in the amplification of the forces and displacement. The increase in wall displacement may arrive at 3 times in silty gravel soil in comparison to hard one. Also, the increase in displacement is accompanied by an increase in the stresses in the tank elements. In addition, the liquid wave height (sloshing) increases by a higher ratio in the case of silty gravel soil than in hard one. The results emphasize the necessity of considering the type of foundation soil for underground reservoirs and the seismic characteristics of the applied recordings. Additionally, it highlights the importance of improving the soil layers on which the foundations of the reservoirs are established, particularly for silty gravel soils.